Overview on the profile measurement of turbine blade and its development Huang Junhui a , Wang Zhao a , Gao Jianmin a , Yanguang Yu b a Institute of Manufacturing System and Quality Engineering, School of Mechanical Engineering Xi'an Jiaotong University, China; b School of Electrical, Computer and Telecommunications Engineering University of Wollongong, Australia ABSTRACT Turbine machinery has an extraordinary wide range of applications in the aviation, aerospace, automotive, energy and many other industries. The turbine blade is one of the most important parts of turbine machinery, and the characteristic parameters, pressure ratio of the engine and rotating speed of the turbine are all related to the shape and size of blades. Therefore, the profile measurement of turbine blade is an essential issue in the blade machining processing, however, it is difficult and particular to establish the profile measurement of turbine blade because of its complicated shapes and space angles of the blades, and the specific stringent environmental requirements need a more appropriate measurement method to the Turbine Blade profile measurement. This paper reviews the recent research and development on the Turbine Blade profile measurement methods, which mainly describes several common and advanced measurement methods, such as the traditional coordinate measuring machines, some optical measurement methods with the characteristics of non-contact like optical theodolite, three-dimensional photography, laser interferometry, as well as the laser triangulation method studied more recently and so on. Firstly, the measuring principles, the key technical issues and the applications in the Turbine Blade profile measurement of the methods which are mentioned above are described respectively in detail, and the characteristics of those methods are analyzed in this paper. Furthermore, the scope of application and limitations of those measurement methods are summed up. Finally, some views on the current research focus and perspective trend of the Turbine Blade profile measurement technology are presented. Keywords: Turbine blade, profile measurement, coordinate measurement machine, optical theodolite, three-dimensional photography, laser interferometry, laser triangulation method 1. INTRODUCTION Turbine blade is a common key part in engineering machinery and equipments, such as the wheel of hydropower generating units, blades of gas turbine and so on. And the profile, surface quality and manufacturing precision of the blades directly impact the turbine performance, efficiency and service life. However, due to the complicated shapes and space angles of the blade, it is difficult and particular to measure. The traditional model measurement is the earliest method applied in the profile measurement of turbine blade, but it has been gradually replaced by the CMM and other methods because of not satisfying the requirements of high measurement precision and efficiency. With the improvement of production efficiency, the CMM is so low on measurement efficiency and so easily influenced by the environment that it needs a more appropriate method to meet the needs of fast detection and on-site measurement and replace the CMM. Then some optical measurement methods, such as the optical theodolite, three-dimensional photography, laser triangulation method, are gradually applied in the profile measurement of turbine blade. These methods have the characteristic of measuring faster, less impact on the environment; especially the latter two methods have higher measurement precision and are easily to implement, so they have a wider application in the profile measurement. In some special occasions, it requires greater precision to inspect the manufacturing quality of blade surface, such as the roughness of blade surface, and those optical measurement methods can't meet the need of higher detection accuracy. And the laser interferometry technique has been applied in the measurement of surface micro-structure, but this technique has a limit of so small measuring range, while using interference fringe projection can solve it in another way. The measurement range becomes larger, but precision lower. Thus the interference fringe projection method is usually applied in the occasion of lower accuracy for large size measurements. With the development of three-dimensional 5th International Symposium on Advanced Optical Manufacturing & Testing Technologies: Optical Test and Measurement Technology and Equipments, edited by Yudong Zhang, Jose M. Sasian, Libin Xiang, Sandy To, Proc. of SPIE Vol. 7656, 76560L · © 2010 SPIE · CCC code: 0277-786X/10/$18 · doi: 10.1117/12.865466 Proc. of SPIE Vol. 7656 76560L-1 Downloaded from SPIE Digital Library on 12 Oct 2010 to 117.32.153.142. Terms of Use: http://spiedl.org/terms